[AndyJ]

The other option if your driving a Diesel would be cooking oil. Apperantly thats good and quite cheap...

[Boboff]

Pure Sunflower Oil has increased to about the same price as diesel now. Last January you could buy oil at 56p a litre, it's £1.39 now.

You can use "used" oil, but then you have to filter it and treat it, and collect it etc, and I wonder if it's worth it, plus you have to tune your car to expect say a 50:50 ratio, so you always need to have desiel in it. If you get the mix out, it can blow your head, min £2k to fix on most desiels !

Nothing is ever easy is it.